Dielectric ceramic capacitor comprising non-reducible dielectric

ABSTRACT

A dielectric ceramic, and capacitor with the ceramic, wherein the ceramic has: about 94-99.9 wt % a first component defined by Formula 1; 
 
[(Ca 1-x Sr x )O] m (Zr 1-y Ti y )O 2   Formula 1
wherein: x is no more than about 0.6; and y is no more than about 0.1; and m is at least about 0.85 to no more than about 1.15; and about 0.1-5 wt % a secondary component defined by Formula 2; 
 
 a SiO 2 - b [αB 2 O 3 —(1-α)Li 2 O]- cA O  Formula 2
wherein: 
 
a, b and c are selected to lie within the region defined by points A(a=15, b=0, c=85), B(a=70, b=0, c=30), C(a=0, b=70, c=30) and D(a=0, b=15, c=85) of a ternary diagram wherein a is mole percent SiO2; b is mole percent αB 2 O 3 —(1-α)Li 2 O; and c is mole percent AO and a+b+c=100 including the lines BC, CD and AD but excluding the line AB; 
a is 0 to 1; A is selected from Mg, Ca, Sr, Ba or a combination thereof; and 
 
0-2 wt % MnO 2 .

BACKGROUND OF THE INVENTION

The present invention relates to a dielectric ceramic capacitorcomprising alternating layers of electrodes and ceramic wherein theceramic comprises calcium zirconium compounds in a main component.

Ceramic capacitors are known to comprise alternating layers of innerelectrodes and ceramic dielectric. There has been, and continues to be,a desire to lower the cost of capacitors without sacrificing thequality. There has also been, and continues to be, a desire to lower thesize of capacitors without sacrificing either the quality orcapacitance. These desires are often at odds leading those of skill inthe art towards continual efforts to advance the art of capacitors andthe manufacture thereof.

One advance is the use of nickel as the electrode metal. Nickel hasadvantages in that the cost is low compared to noble metals such assilver and palladium and the resistance properties are suitable for usein a capacitor. One disadvantage with nickel is the propensity tooxidize under those conditions required to sinter the ceramicdielectric. The problem associated with oxidation has been mitigated bysintering the ceramic in reducing atmosphere thereby insuring that themetal remains in the metallic state. Unfortunately, ceramics sintered inreducing atmosphere have a lower specific resistance which is highlyundesirable. This has led to an ongoing effort to develop non-reducibledielectric ceramics which can be sintered in a reducing atmosphere belowthe melting temperature of nickel.

Towards this goal diligent efforts have led to the development of anon-reducible ceramic which can be sintered in reducing atmospherewithout detriment to the electrode thereby yielding a capacitor withhigh electrode continuity and excellent electrical properties.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a capacitor withimproved properties.

It is another object of the present invention to provide a capacitorwith a nickel electrode having excellent electrode continuity.

It is yet another object of the present invention to provide a ceramicwhich can be fired in reducing atmosphere without loss of resistance.

It is another object of the present invention to provide a capacitorwith an improved ceramic dielectric.

A particular feature of the present invention is the ability to sinterthe ceramic in reducing atmosphere while maintaining a sufficiently highspecific resistance for the dielectric.

A particular advantage of the present invention is the ability to sinterthe ceramic in reducing atmosphere at below 1400° C.

These and other advantages, as will be realized, are provided in adielectric ceramic comprising: about 94-99.9 wt % of a first componentdefined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1wherein:x is no more than about 0.6; andy is no more than about 0.1; andm is at least about 0.85 to no more than about 1.15; andabout 0.1-5 wt % of a secondary component defined by Formula 2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2wherein:a, b and c are selected to lie within the region defined by pointsA(a=15, b=0, c=85), B(a=70, b=0, c=30), C(a=0, b=70, c=30) and D(a=0,b=15, c=85) of a ternary diagram wherein a is mole percent SiO₂; b ismole percent αB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100including the lines BC, CD and AD but excluding the line AB;α is 0 to 1;A is selected from Mg, Ca, Sr, Ba or a combination thereof; and0-2 wt % MnO₂.

Yet another embodiment is provided in a laminated ceramic capacitor witha plurality of inner electrode layers, a plurality of dielectric layersbetween the inner electrode layers and external electrodes in electricalconductivity with the inner electrode layers. The dielectric layers havea ceramic defined as:

about 94-99.9 wt % of a first component defined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1wherein:x is no more than about 0.6; andy is no more than about 0.1; andm is at least about 0.85 to no more than about 1.15; andabout 0.1-5 wt % of a secondary component defined by Formula 2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2wherein:a, b and c are selected to lie within the region defined by pointsA(a=15, b=0, c=85), B(a=70, b=0, c=30), C(a=0, b=70, c=30) and D(a=0,b=15, c=85) of a ternary diagram wherein a is mole percent SiO2; b ismole percent αB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100including the lines BC, CD and AD but excluding the line AB;α is 0 to 1;A is selected from Mg, Ca, Sr, Ba or a combination thereof; and0-2 wt % MnO₂.

Yet another embodiment is provided in a dielectric ceramic with:

about 95-99.5 wt % of a first component defined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1wherein:x is no more than about 0.6; andy is no more than about 0.1; andm is at least about 0.85 to no more than about 1.15; andabout 0.35 to about 4 wt % of a secondary component defined by Formula2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2wherein:a, b and c are selected to lie within the region defined by pointsA(a=15, b=0, c=85), B(a=70, b=0, c=30), C(a=0, b=70, c=30) and D(a=0,b=15, c=85) of a ternary diagram wherein a is mole percent SiO2; b ismole percent αB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100including the lines BC, CD and AD but excluding the line AB;α is 0 to 1;A is selected from Mg, Ca, Sr, Ba or a combination thereof; andabout 0.2 to about 1.5 wt % MnO₂.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 is a cross-sectional view of a capacitor of the presentinvention.

FIG. 2 is a ternary diagram of SiO₂, αB₂O₃—(1α)Li₂O and AO.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be described with reference to the accompanyingdrawings forming an integral part of the present disclosure.

A cross-sectional view of a capacitor of the present invention isillustrated schematically in FIG. 1. In FIG. 1, the capacitor, generallyrepresented at 10, comprises a multiplicity of conductive innerelectrodes, 11, with ceramic, 12, dispersed there between. Alternatinglayers of the conductive layer terminate at opposing external terminals,13, of opposite polarity. An insulating layer, 14, may be applied.

The dielectric ceramic layers, 12, are composed of a dielectric ceramiccomposition comprising a primary component defined by Formula 1.[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1wherein: x is no more than 0.6, y is no more than 0.1, and m is at least0.85 to no more than 1.15. When x is above about 0.6 the temperaturecoefficient of capacitance becomes too large. When y is above about 0.1the temperature coefficient of capacitance is not acceptable, thequality factor Q is lower and the ceramic becomes more sensitive toreduction.

More preferably x, in formula 1 is at least 0.1 and no more than about0.5. Even more preferably x, in formula 1, is at least about 0.2 to nomore than about 0.4.

More preferably y, in formula 1 is at least about 0.01 and no more thanabout 0.07. Even more preferably y, in formula 1, is at least about 0.02to no more than about 0.05.

In addition to the primary component the dielectric ceramic compositioncomprises a secondary component defined by formula 2:aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2wherein: a represents the molar percent of silicon dioxide, b representsthe molar percent of boron oxide or lithium oxide or any combinationthereof (0≦α≦1), and c represents the molar percent of at least onealkaline earth oxide chosen among oxides of magnesium, calcium,strontium, barium and any combinations thereof. The SiO₂ content a, the(B₂O₃—Li₂O) content b, and the alkaline earth oxide content c in thesecondary component preferably lie within the region surrounded bypoints A(a=15, b=0, c=85), B(a=70, b=0, c=30), C(a=0, b=70, c=30) andD(a=0, b=15, c=85) of the ternary diagram of FIG. 2 including the linesBC, CD and AD but excluding the line AB. The secondary component asdefined by formula 2 can be added in a variety of forms, such as, asingle phase compound, a multi-phase compound, or a mixture thereof,wherein each compound can be, but is not limited to: a glass powder, asingle-element or a multi-element oxide, a carbonate, a pure element, ametal-organic compound, a metal alkoxide, a sol-gel derived powder, andany possible combination thereof leading after sintering to a secondarycomponent of general formula aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO.

Above a mole percent of silicon dioxide of about 70 mole %, indicated asoutside of line BC in the ternary diagram of FIG. 2 and toward the SiO₂pole (a>70), the sintering temperature increases. In a particularlypreferred embodiment the mole percent of silicon dioxide, in formula 2is about 20 to 30 mole %.

Above a mole percent of boron oxide-lithium oxide combination of about70 mole %, indicated as outside of line BC of the ternary diagram ofFIG. 2 and toward the B₂O₃—Li₂O pole (b>70), the physical properties ofthe ceramic are inferior. In a particularly preferred embodiment themole percent of boron oxide and/or lithium oxide, in formula 2 is about15 to 30 mole %.

Above a mole percent of AO of about 85 mole % (c>85) the sinteringtemperature increases too much. More preferably the mole percent of AOin formula 2 is at least about 40 mole % and no more than about 70 mole%. In a particularly preferred embodiment the mole percent of AO, informula 2 is about 42 to 60 mole %.

The dielectric ceramic composition preferably comprises at least 94 wt %primary component to no more than 99.9 wt % primary component. Belowabout 94 wt % primary component the dielectric constant is too low.Above about 99.9 wt % primary component the sintering temperatureincreases too much. More preferably the primary component is present inan amount of at least about 95 wt % to no more than about 99.5 wt %.Even more preferably the primary component is present in an amount of atleast about 96 wt % to no more than about 99 wt %.

The dielectric ceramic composition preferably comprises at least 0.1 wt% secondary component to no more than 5 wt % secondary component. Belowabout 0.1 wt % secondary component the densification is poor. Aboveabout 5 wt % secondary component the dielectric constant is loweredunacceptably. More preferably the secondary component is present in anamount of at least about 0.35 wt % to no more than about 4 wt %. Evenmore preferably the secondary component is present in an amount of atleast about 0.8 wt % to no more than about 2.5 wt %.

The dielectric ceramic composition may also comprise MnO₂ in an amountof up to 2 wt %. While not limited to any theory the MnO₂ is believed toimprove sinterability and improve insulation resistance of the firedceramic. It is more preferred that the MnO₂ be present in an amount ofat least about 0.2 wt % to no more than about 1.5 wt %. Most preferablythe MnO₂ is present in an amount of at least about 0.3 wt % to no morethan about 1 wt %.

The dielectric of the present invention can be used to prepare alaminated ceramic capacitor with excellent insulation resistance, highreliability and which can be fired at below 1300° C. in reducingatmosphere without causing the ceramic to become semi-conductive. Theresulting ceramic has a small temperature coefficient of capacitance(TCC) between −30 and +30 ppm/° C. in the temperature range of −55° C.to +125° C., meeting EIA COG specification. Here TCC(t) where t istemperature in ° C. is defined by:TCC(t)=10⁶×[Cap(t)−Cap(25)]/[Cap(25)×(t−25)] where Cap(t) is thecapacitance of the device at temperature t. The resulting ceramic alsohas a dielectric constant of about 35. Further advantages of theinventive ceramic includes a long accelerated lifetime of insulatingresistance.

The primary component preferably has a mean particle size of about 0.5to 1.0 μm.

The inner electrodes, 11, are composed of a base metal such as nickel,copper, chromium or an alloy thereof. Most preferably the base metal isnickel since the advantages of nickel can be fully exploited with theinventive ceramic.

The composition of the external end terminations, 13, is notparticularly limiting herein and any composition typically employed inthe art is sufficient. Silver, palladium, copper, nickel or alloys ofthese metals blended with various glass frits are particularly relevant.A plating layer or multiple plating layers can be formed on the externalend terminations.

The preparation of laminated ceramic capacitors are well documented andthe present invention does not alter the manufacturing process to anysignificant degree relative to standard procedures known in the art.

As an example of a manufacturing process, a ceramic slurry is preparedby blending and milling the ceramic compounds described herein with adispersant in either water or an organic solvent such as, for example,ethanol, isopropanol, toluene, ethyl acetate, propyl acetate, butylacetate or a blend thereof. After milling a ceramic slip is prepared fortape-casting by adding a binder and a plasticizer to control rheologyand to give strength to the tape. The obtained slip is then processedinto a thin sheet by tape-casting. After drying the sheet, amultiplicity of electrodes are patterned on the sheet by using, forexample, a screen-printing method to form printed ceramic sheet.

A laminate green body is prepared by stacking onto a substance such aspolycarbonate, polyester or a similar method: 1) a certain number ofunprinted ceramic sheets representing the bottom covers, then 2) acertain number of printed ceramic sheets in alternate directions so asto create alternating electrodes that terminate at opposing ends, and 3)a certain number of unprinted ceramic sheets representing the topcovers. Variations in the stacking order of the printed and unprintedsheets can be used with the dielectric material of this invention. Thestack is then pressed at between 20° C. and 120° C. to promote adhesionof all laminated layers.

The laminated green body is then cut into individual green chips.

The green chip is heated to remove the binder. The binder can be removedby heating at about 200-400° C. in atmospheric air or slightly reducingatmosphere for about 0.5 to 48 hours.

The dielectric is then sintered in a reductive atmosphere with an oxygenpartial pressure of 10⁻⁸ to 10⁻¹² atm at a temperature not to exceed1300° C. The preferred temperature is about 1,200 to 1,300° C. Aftersintering the dielectric is reoxidized by heating to a temperature of nomore than about 1,100° C. at an oxygen partial pressure of about 10⁻⁵ to10⁻¹⁰ atm. More preferably, the reoxidation is done at a temperature ofabout 800 to 1,100° C. The material resulting from this stage istypically referred to as a sintered chip.

The sintered chip is subjected to end surface grinding by barrel or sandblast, as known in the art, followed by transferring outer electrodepaste to form the external electrodes. Further baking is then done tocomplete the formation of the outer electrodes. The further baking istypically done in nitrogen atmosphere at a temperature of about600-1000° C. for about 0.1 to 1 hour.

Layers of nickel and tin can then be plated on the outer electrodes toenhance solderability and prevent oxidation of the outer electrodes.

EXAMPLES

A powder of [(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂ was used as theprimary component in all the following examples. The powder was preparedby calcination from CaCO₃, SrCO₃, ZrO₂ and TiO₂ in ratios to achieve acomposition with x=0.3, y=0.03 and m=1.000. The typical median particlesize of the calcined powder was 0.7 μm and the specific surface area was4.5m²/g. Glass powders for the secondary components were obtained bymixing raw materials of CaCO₃, SrCO₃, SiO₂ and B₂O₃, melting, quenchingand milling. Table 1 gives the formulation of the glass powders used.TABLE 1 Glass SiO2 B2O3 CaO SrO Powder No. (mol %) (mol %) (mol %) (mol%) A 30 20 50 0 B 30 20 35 15 C 30 20 20 30

Ceramic formulations were prepared by mixing and milling mixtures of theprimary component, a secondary component (glass powder+additive) andmanganese dioxide in water with a binder and plasticizer in order toprepare ceramic slurries. Table 2 and 3 give the ceramic formulationsprepared with this process. Table 2 gives the actual wt % of eachmaterial used and the mean particle size (D50) of the ceramic slurryafter milling. Table 3 gives the resulting compositions of the secondarycomponent only (glass+additive CaCO₃ and SrCO₃), after conversion of thecarbonates into oxides. TABLE 2 Primary Component Glass Glass PowderCaCO₃ additive SrCO₃ additive MnO₂ D50 After Sample No. wt % Powder wt %wt % wt % wt % Milling (μm) 1 99 A 0.5 0 0 0.5 0.65 2 97.7 A 1.2 0 0.60.5 0.63 3 97.7 A 1.2 0 0.6 0.5 0.63 4 96.675 A 1.2 0 1.625 0.5 0.64 598 A 1.5 0 0 0.5 0.62 6 97.262 A 1.5 0 0.738 0.5 0.64 7 96.56 A 2 00.639 0.8 0.64 8 95.9 A 2.5 0 0.799 0.8 0.68 9 97.511 B 1.2 0.787 0.0010.5 0.66 10 96.818 B 2 0.417 0.264 0.5 0.65 11 96.318 B 2 0.417 0.264 10.63 12 97.398 C 1.2 0.865 0.035 0.5 0.64

TABLE 3 Secondary Component Composition SiO₂ B₂O₃ CaO SrO Sample No.(mol %) (mol %) (mol %) (mol %) 1 30.0 20.0 50.0 0 2 24.9 16.6 41.6 16.93 24.9 16.6 41.6 16.9 4 19.4 12.9 32.3 35.4 5 30.0 20.0 50.0 0 6 25.016.7 41.6 16.7 7 26.6 17.7 44.2 11.5 8 26.6 17.7 44.2 11.5 9 20.8 13.954.8 10.5 10 25.0 16.7 40.8 17.5 11 25.0 16.7 40.8 17.5 12 19.4 12.947.4 20.3

Next, the ceramic slurries were formed into sheets by the doctor blademethod. The thickness of the sheet was controlled to obtain dielectricthicknesses of about 6 μm after firing. A conductive paste primarilycomposed of nickel was then applied on the ceramic green sheet byscreen-printing so as to form the internal electrodes of a monolithicceramic capacitor. A multiplicity of ceramic green sheets withconductive paste were then laminated to form a green multilayerlaminate. Lamination was performed so that in the final multilayercapacitor the electrodes are exposed alternately on both ends. Thelaminate thus formed was then cut to desired dimensions and heated tobetween 200 and 400° C. in atmospheric air or slightly reducingatmosphere to burn out the organic components of the green laminate.Subsequently, the laminate was sintered at a temperature shown in Table4 in a reducing atmosphere of N₂—H₂—H₂O to form a sintered ceramic body.A copper paste was then applied to both ends of the sintered body toform external electrodes electrically connected to the internal nickelelectrodes. The outer dimensions of the finished multilayer ceramiccapacitors were 2.0 mm in length by 1.25 mm in width by 1.25 mm inthickness. The thickness and number of dielectric layers were 6 μm and73 respectively.

The electrical properties of the capacitors were then determined.Electrostatic capacitance and Dissipation Factor were measured at 1 V, afrequency of 1 MHz and a temperature of 25° C. The average capacitancewas about 3800 pF. The relative dielectric constant was calculated fromthe electrostatic capacitance, the dimensions of the internal electrodesand the dielectric thickness. Insulation resistance was measured at 125°C. by applying a voltage of 50V with a charging time of 60 seconds. Thetemperature coefficient of capacitance (TCC) was calculated based oncapacitance measurements at −55° C., +25° C. and +125° C. TCC(t) at atemperature t was calculated (in ppm/° C.) using the following equation:TCC(t)=10⁶×[Cap(t)−Cap(25)]/[Cap(25)×(t−25)] where Cap(t) is thecapacitance of the capacitor at temperature t, in ° C. Finally, highlyaccelerated life test (HALT) was performed on 20 capacitors bymonitoring the insulation resistance at a temperature of 175° C. and avoltage of 400V during 92 h. Median Time To Failure (MTTF) are reportedin minutes. If more than 50% of the capacitors in a sample did not failat 92 h, the MTTF is reported as >5520 min. The results of theelectrical characterization are summarized in Table 4. TABLE 4 PeakFiring Insulation D50 After Temperature Dielectric Dissipationresistance at 125° C./ Breakdown TCC TCC MTTF Sample No. Milling (μm) (°C.) Constant K Factor (%) 50 V (G ohms) Voltage (V) at −55° C. at +125°C. (min) 1 0.65 1225 30.7 0.007 1269 649 −23.1 −1.9 >5520 2 0.63 120030.8 0.008 1009 907 −20.1 −0.7 >5520 3 0.63 1250 33.3 0.009 2052 945−23.1 −2.4 >5520 4 0.64 1225 33.6 0.010 270 745 −25.3 0.6 >5520 5 0.621200 31.0 0.012 2416 986 −19.6 1.4 3870 6 0.64 1250 32.2 0.008 2262 742−21.8 −1.2 >5520 7 0.64 1250 33.3 0.010 2990 824 −15.6 4.3 >5520 8 0.681250 28.7 0.013 3123 888 −13.7 5.9 3533 9 0.66 1225 30.5 0.009 345 597−23.1 −0.1 >5520 10 0.65 1250 32.8 0.010 3236 672 −22.3 −1.0 >5520 110.63 1250 32.5 0.009 324 789 −15.7 2.8 >5520 12 0.64 1225 33.2 0.009 202503 −25.0 −2.1 >5520

In conclusion, samples 1 through 12 have high insulation resistanceabove 200 GΩ at 125° C., a dissipation factor less than 0.1%, highbreakdown voltage and a TCC in the range −32.3 to −13.7 ppm/° C. at −55°C. and in the range −6.4 to 5.9 ppm/° C. at +125° C. when fired at orbelow 1300° C. in reducing conditions compatible with Ni electrodes. Theaverage median time to failure in a highly accelerated life test at 175°C., 400V is greater than 92 h.

The invention has been described with particular emphasis on thepreferred embodiments without limit thereto. One of skill in the artwould realize from the teachings herein alternate embodiments which arewithin the metes and bounds of the claims appended hereto.

1. A dielectric ceramic comprising: about 94-99.9 wt % a first componentdefined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1 wherein: x is nomore than about 0.6; and y is no more than about 0.1; and m is at leastabout 0.85 to no more than about 1.15; and about 0.1-5 wt % a secondarycomponent defined by Formula 2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2 wherein: a, b and c are selectedto lie within the region defined by points A(a=15, b=0, c=85), B(a=70,b=0, c=30), C(a=0, b=70, c=30) and D(a=0, b=15, c=85) of a ternarydiagram wherein a is mole percent SiO2; b is mole percentαB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100 including thelines BC, CD and AD but excluding the line AB; α is 0 to 1; A isselected from Mg, Ca, Sr, Ba or a combination thereof; and 0-2 wt %MnO₂.
 2. The dielectric ceramic of claim 1 comprising about 95 to about99.5 wt % of said first component.
 3. The dielectric ceramic of claim 2comprising about 96 to about 99 wt % of said first component.
 4. Thedielectric ceramic of claim 1 comprising about 0.35 to about 4 wt % ofsaid second component.
 5. The dielectric ceramic of claim 4 comprisingabout 0.8 to about 2.5 wt % of said secondary component.
 6. Thedielectric ceramic of claim 1 comprising about 0.2 to about 1.5 wt %MnO₂.
 7. The dielectric ceramic of claim 6 comprising about 0.3 to about1 wt % MnO₂.
 8. The dielectric ceramic of claim 1 wherein x is at leastabout 0.1 to no more than about 0.5.
 9. The dielectric ceramic of claim8 wherein x is at least about 0.2 to no more than about 0.4.
 10. Thedielectric ceramic of claim 1 wherein y is about 0.01 to about 0.07. 11.The dielectric ceramic of claim 10 wherein y is about 0.02 to about0.05.
 12. The dielectric ceramic of claim 1 wherein a is about 20 toabout
 30. 13. The dielectric ceramic of claim 1 wherein b is about 15 toabout
 30. 14. The dielectric ceramic of claim 1 wherein c is about 40 toabout
 70. 15. The dielectric ceramic of claim 14 wherein c is about 42to about
 60. 16. A capacitor comprising a dielectric of claim
 1. 17. Alaminated ceramic capacitor comprising: a plurality of inner electrodelayers; a plurality of dielectric layers between said inner electrodelayers wherein said dielectric layers comprise a ceramic comprising:about 94-99.9 wt % a first component defined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1 wherein: x is nomore than about 0.6; and y is no more than about 0.1; and m is at leastabout 0.85 to no more than about 1.15; and about 0.1-5 wt % a secondarycomponent defined by Formula 2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2 wherein: a, b and c are selectedto lie within the region defined by points A(a=15, b=0, c=85), B(a=70,b=0, c=30), C(a=0, b=70, c=30) and D(a=0, b=15, c=85) of a ternarydiagram wherein a is mole percent SiO2; b is mole percentαB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100 including thelines BC, CD and AD but excluding the line AB; α is 0 to 1; A isselected from Mg, Ca, Sr, Ba or a combination thereof; and 0-2 wt %MnO₂; and external electrodes in electrical conductivity with said innerelectrode layers.
 18. The dielectric ceramic of claim 17 comprisingabout 95 to about 99.5 wt % of said first component.
 19. The dielectricceramic of claim 18 comprising about 96 to about 99 wt % of said firstcomponent.
 20. The laminated ceramic capacitor of claim 17 comprisingabout 0.35 to about 4 wt % of said secondary component.
 21. Thelaminated ceramic capacitor of claim 17 wherein x is at least about 0.1to no more than about 0.5.
 22. The laminated ceramic capacitor of claim21 wherein x is at least about 0.2 to no more than about 0.4.
 23. Thelaminated ceramic capacitor of claim 17 wherein y is about 0.01 to about0.07.
 24. The laminated ceramic capacitor of claim 17 wherein y is about0.02 to about 0.05.
 25. The laminated ceramic capacitor of claim 17wherein a is about 20 to about
 30. 26. The laminated ceramic capacitorof claim 17 wherein b is about 15 to about
 30. 27. The laminated ceramiccapacitor of claim 17 wherein c is about 40 to about
 70. 28. Thelaminated ceramic capacitor of claim 17 comprising about 0.2 to about1.5 wt % MnO₂.
 29. The laminated ceramic capacitor of claim 28comprising about 0.3 to about 1 wt % MnO₂.
 30. The laminated ceramiccapacitor of claim 17 wherein said inner electrode layers comprise ametal.
 31. The laminated ceramic capacitor of claim 17 wherein saidmetal is nickel.
 32. A dielectric ceramic comprising: about 95-99.5 wt %a first component defined by Formula 1;[(Ca_(1-x)Sr_(x))O]_(m)(Zr_(1-y)Ti_(y))O₂  Formula 1 wherein: x is nomore than about 0.6; and y is no more than about 0.1; and m is at leastabout 0.85 to no more than about 1.15; and about 0.1 to about 5.0 wt % asecondary component defined by Formula 2;aSiO₂-b[αB₂O₃—(1-α)Li₂O]-cAO  Formula 2 wherein: a, b and c are selectedto lie within the region defined by points A(a=15, b=0, c=85), B(a=70,b=0, c=30), C(a=0, b=70, c=30) and D(a=0, b=15, c=85) of a ternarydiagram wherein a is mole percent SiO2; b is mole percentαB₂O₃—(1-α)Li₂O; and c is mole percent AO and a+b+c=100 including thelines BC, CD and AD but excluding the line AB; α is 0 to 1; A isselected from Mg, Ca, Sr, Ba or a combination thereof; and about 0 toabout 2 wt % MnO₂.
 33. The dielectric ceramic of claim 32 comprisingabout 96 to about 99 wt % of said first component.
 34. The dielectricceramic of claim 32 comprising about 0.35 to about 4 wt % of saidsecondary component.
 35. The dielectric ceramic of claim 32 wherein x isat least about 0.1 to no more than about 0.5.
 36. The dielectric ceramicof claim 35 wherein x is at least about 0.2 to no more than about 0.4.37. The dielectric ceramic of claim 32 wherein y is 0.01 to 0.07. 38.The dielectric ceramic of claim 32 wherein a is about 20 to about 30.39. The dielectric ceramic of claim 32 wherein b is about 15 to about30.
 40. The dielectric ceramic of claim 32 wherein c is about 40 toabout
 70. 41. A capacitor comprising the dielectric of claim 32.